Momentary switches



Jan. 9, 1962 H. E. HAGBERG MOMENTARY SWITCHES 3 Sheets-Sheet 1 FiledJuly 9, 1959 E Q mw .Rl uw mw @www E Nw mm uw uw .Nw w. 11. -R wm wm. .lw d w PQ m m uw: Nm wn w\ "w ww R uw ww .m. Nn .1w R l N ww d N 3 mm fVNHMN f v. wm wm Nw mw .Sw mw mm.. i mw i mum. g WM inw g um. s w M R MNn mw ww INVENTOR M/a E. #naamw BY I @QWW ATTOR EY Jan. 9, 1962 H. E.HAGBERG 3,016,439

MOMENTARY SWITCHES 5 Sheets-Sheet 2 Filed July 9, 1959 lq. L

Jan. 9, 1962 H. E. HAGBERG MOMENTARY SWITCHES 3 Sheets-Sheet 5 FiledJuly 9. 1959 QM. m.m..%\ Nb mb um mw E ATTORNEY United States Patent3,016,439 MOMENTARY SWITCHES Hugo E. Hagberg, West Hartford, Conn.,assigner to Carling Electric, Inc., West Hartford, Conn., a corporationof Connecticut Filed July 9, 1959, Ser. No. 825,969 23 Claims. (Cl.200--159) This invention relates to switches, and particularly toimprovements in momentary switches.

A salient feature of the present invention is the provision of a simplemomentary switch assembly which is openative to maintain either anormally closed circuit or a normally open circuit by the use ofsubstantially identical parts except for the alternative use of eitherof two springs having somewhat diilerent characteristics and beingplaced in slightly different positions in the assembly relative to theother parts.

Another important feature of the present invention is the provision ofmomentary switches of improved structure wherein opposing spring forcesare utilized to obtain positive circuit closing contact action andpositive circuit opening contact release, while at the same timeexcessive contact pressures are obv-iated by overtravel arrangements forthe actuating elements thereof.

Still other objects and advantages of the invention will be apparentfrom the specication.

The features of novelty which are believed to be characteristic of theinvention are set forth herein and will best be understood, both as totheir fundamental principles and as to their particular embodiments, byreference to the specification and accompanying drawings, in which:

FIGURE l is a perspective view of a typical switch assembly embodyingthe present invention;

FIG. 2 is a greatly enlarged vertical section view taken on line 2-2 ofFIG. l, some parts being shown in section 'and some parts being shown inelevation, and showing the contacting elements normally closed;

FIG. 3 is similar to PIG. 2, showing the arrangement of the elementsafter the plunger has been depressed momentarily to open the contactelements;

FIG. 4 is a view taken on line 4-4 of FIG. 2, some parts being brokenaway and some parts in section;

FIG. 5 is a view taken on line 5-5 of FIG. 2, some parts in section andsome parts broken away;

FIG. 6 is a view taken on line 6-#6 of FIG. 2, some parts being shown inphantom outline, some in section, and some parts being shown inelevation; Y

FIG. 7 is a view taken on line 7-7 of FIG. 2, some parts being shown inelevation and some in section;

FIG. 8 is a greatly enlarged exploded view of the I contact levers andtheir relationship to their supporting yoke, to the plunger -rod landthe contact bar;

FIG. 9 is a view similar to FIG. 2, showing an e-mbodiment wherein thecontacting elements of the switch are normally open;

FIG. l0 is a view similar to FIG. 3, showing the normally open switch ofFIG. 9 having been closed momentarily by the depression of the plunger;and

FIG. 1l is a greatly enlarged, partial section, fragmentary view of oneof the actuating elements for the contact levers.

Referring now to the drawings in detail, wherein similar .parts aredesignated by the same reference numerals throughout, the switches ofthe present invention comprise the box like molded base, generallydesignated 21, made of a suitable synthetic thermosetting resin such asBakelite, or the like, and having a pair of opposing end walls 22 and apair of side walls 23. The bottom of base 21 is enclosed by a oor 24.

The top of base 21 of a suitable material such as sheet metal or iscovered by a top plate 25 made the like,

f ice and whose ends are coextensive with the outer surfaces ofrespective end walls 22. The sides of top plate 25 are recessed tocoincide with recesses 26 in the outer surfaces of side walls 23 of base21. FIGS. 4, 5. Top plate 25 has a central aperture 27 through whichvarious switch elements project as will be described hereinbelow.

Positioned over top plate 25 is a bracket 31 of sheet metal having acentral circular aperture positioned substantially coaxially in respectof aperture 27 of top plate 25, and surrounded by an upset circularcollar 32. Bracket 31 has a pair Aof downwardly extending leaves 33which lit within the recesses 26 of side walls 23. The lower end of eachleaf 3G is provided with a pair of spaced apart lugs 34 which extendinto respective recesses 35 in the bottom floor 24 of base 21. FIGS. 4,6. Lugs 34 t snugly into recesses 35 whereby bracket 31 secures topplate 25 firmly to the top of base 21.

A suitable bushing 37 having peripheral threading 38 is provided at itslowei end with an annular l-ip 39 forming an interlocking connectionwith collar 32 of bracket 31 whereby said bushing is secured rmly tobase 21. Bushing 37 has a pair of coaxially aligned central apertures 41and 42, the latter being of somewhat greater diameter than the former.Said apertures are separated from eachother by means of an annularcollar 43 intermediate the ends of said bushing. Bushing 37 and base 21together form a frame or closure for the operative elements of theswitches described herein.

Positioned within the upper aperture 41 and movable longitudinallytherein is a tubular plunger 44 having a head 45 of enlarged diameterwhich limits the downward movement of said plunger into said aperturewhen said head bears upon the top end of bushing 37. The lower portionl46 of plunger 44 is reduced in outside diameter to accommodate coilspring 47, the lower end of which bears against the top of coll-ar 43and the upper end of which bears against shoulder 48 in order normallyto urge plunger `44 upwardly into a non-operating condition. The lowerend of plunger'44 is provided with an annular llange -49 which engagesthe lower surface of collar 43 to limit the upward movement of saidplunger underthe action of spring 47.

Plunger 414 has a longitudinal central aperture 51 which is enclosedat'the top and open iat the bottom. Aperture 51 accommodates anelongated pin 52 that is movable longitudinally therein. Aperture 51also accommodates a coaxial spring 53, the lower end of which bea-rsyieldably up on the top of ypin 52 normally urging the latter downwardlyout of said aperture. Pin 52 is made of a suitable plastic, rubber orother insulating material which is suciently rigid and strong towithstand a great number of actuations.

Positioned in iloorY 24 of base 21 is a pair of spaced apart,electrically conducting studs 56 which extend through said floor andareincorporated securely therein by means of molding or otherwise. Eachstationary stud 56 has a contact head 57 which extends into the interiorof base 21. The lower ends of studs 56 extend downwardly to the exteriorof base 21 and each has a rivet head 58 which rmly secures anelectricallyV conductive bracket 59 to the bottom of said base. Eachbracket 59 has -a downwardly extending lug which serves as a .terminal61 to which electrical circuitry is connectible.

Secured lirmly tothe central portion of iloor 24 on the interior of base21 by means of rivet 62 is a contact lever support yoke, generallydesignated 63. Yoker63 comprises a.` laterally extending horizontal base64 have` ing integrally formed at each end thereof an upwardly extendingbracket 65 which terminates ina pair of spaced apart upwardly extendingears 66 and 67 FIGS.V Ears 66 and 67 bound horizontal support ridges 68on top of brackets 65. Coacting with yoke 63 is a pair of oppositelyextending identical electrically conducting contact levers 71 and 72.Contact levers 71 and 72, which are separate and independent from eachother, have respective pairs of oppositely extending lugs 73 and 74which rest upon ridges 68 of brackets 65 between ears 66 and 67. Thelower inner edges of lugs 73 and 'i4 serve as fulcrums, intermediate theends of the levers, coacting with ridges 68 to provide pivoting actionfor the respective contact levers 71 and 72.

The outer end of each Contact lever 71 land '72 is provided with anelectrically conductive contact button 76 secured therein by riveting orotherwise, each contact button being adapted to establish electricalconnection with a respective head 57 of contact studs 56.

Intermediate their respective ends, levers 71 and 72 are bent into acuteangle bights 77 and 78, respectively. Coacting simultaneously with bothbights 77 and 78 is a horizontal actuator bar S1 made of a suitableinsulating material, such as resin impregnated fiberboard, Bakelite, orthe like. Actuator bar 81 is normally urged yieldably upon bights 77 and78 by the lower end of spring 82, the upper end of which bears againstthe bottom of collar 43 of bushing 37. It will be noted that spring 82,which surrounds pin 52 and is coaxially aligned with spring 53, extendsinto aperture i2 of bushing 37 and extends freely through aperture 27 intop plate 25.

Actuator bar 81 has a central aperture 83 which permits the freevertical movement of actuator pin 52 therethrough. The lower end of pin52 bears upon the top of a laterally extending electrically conductingcenter contact bar S43, the bottom of which in turn bears upon the topsof both pairs of lugs '73 and 74 o levers 7l and 72, respectively.

It will be observed in FIG. 2, that the switch is in a normally closedposition by reason of contact buttons 76 having established electricalconnection with respective contact heads 57 under the action of spring82 bearing down upon contact bar 81 which in turn bears down on bights77 and 78. Electrical connection between contact levers 71 and 72 isestablished through contact bar S1. In this embodiment, the respectivecharacteristics of springs 53 and 82 are predetermined whereby the forceexerted by spring 31 is normally greater than that of spring S3 so thatin the non-operative position of plunger 44 (FIG. 2), the switch is inthe normally closed electrically conducting condition. Y

When it is desired to open the electrical circuit momentarily, plunger44 is depressed against the action of spring 47 whereby the compressionof spring S3 increases its force upon pin 52 to cause the latter to beardownwardly upon bar 84 which in turn bears downwardly upon lugs 73 and74 to produce a pivoting action upon respective contact levers 71 and72, as shown in FIG. 3. This compression of spring 53 produces suicientforce to overcome the force of spring 82 whereby the latter becomescompressed to permit actuating bar 81 to move upwardly so thatpivoting'contact levers 71 and 72 are enabled to lift contact buttons 76away from their respective contact heads 57, FIG. 3'.

After the momentary opening of the electrical circuit has beenaccomplished, and it is desired to reclose the circuit, pressure isreleased from head 45 of plunger 44 which is automatically returned toits original non-operative position by the action of spring 47, therebydiminishing the force exerted by spring 53 so'that spring 82 is onceagain enabled to cause actuator bar 81 to bear down upon bights 77 and78 and to cause contact levers 71 and 72 to move pivotally back into thecontact closing position shown' in FIG. 2.

The normally closed' switch shown in FIGS. -2 and -3 isreadily convertedinto a normally open switch as illustrated inFIGS. 9 and 10 withoutmaking any substantial change in any of the parts except for thesubstitution of a single' spring.

Sprin 82 (FIGS. 2, 3) is removed and a coiled spring 88 (FIGS. 9, `10)of somewhat smaller diameter is positioned coaxially around actuator pin52, the lower end of said spring 88 bearing upon actuator bar 8l and itsupper end impinging upon and being engageable by flange 49 of plunger44. The characteristics of the respective springs 88 and 53 arepredetermined whereby the normal biasing force exerted by spring 53 uponpin 52 is greater than that exerted by spring 8S so that contact levers71 and 72 are maintained in an open circuit position as shown in FIG. 9.When plunger 44 is depressed against the action of spring 47, thecompression of spring 83 produces sutiicient additional force uponactuating bar 81 to cause contact levers 71 and 72 to move pivotally toclose the electrical circuit between each contact button 76 and itscorresponding contact head 57 as shown in FIG. 10. The increased forceexerted by spring 88 when plunger 44 is depressed is suflicient toovercome the countervailing force of spring 53 so that pin 52 is liftedto permit the pivoting action of contact levers 71 and 72 from theirnormally open position shown in FIG. 9 to their circuit closing positionas shown in FIG. lO.

In both embodiments, FIGS. 2, 3, and FIGS. 9, l0, the opening andclosing of the respective switches take place during a partial downwardstroke of plunger 44 so that when said plunger is depressed beyond thepoint where the contacts make or break the circuit, the energy producedby the continuing stroke of the plunger is absorbed by the operativesprings whereby excessive pressure either upon the cooperating contactsor upon portions of the Contact levers themselves is obviated, therebyconserving as well as prolonging the life of the switch assembly.

In some embodiments, electrically conducting bar 554 may be omitted inwhich case there may be alternatively connected to the lower end oractuating pin 52 an electrically conducting bar S9 (FIG. ll) whichserves to actuate lugs 'and 74 and at the same time conduct theelectrical current therebetween when the respective contact buttons 76and contact heads S7 are in circuit closing position. In otherembodiments, pin 52 may be made of a suitable electrically conductingmetal, the lower end of which impinges upon lugs 73 and 74I of Contactlevers 71 and 72 simultaneousy. In such event, suitable means can bereadily elected for electrically insulating pin 52. from the other partsof the switch.

It will bei noted that in the'norrnaliy closed switch, FIG.,2, thebiasing force of spring 82 upon levers 71 and. 72 onl one side of theirrespective fulcrums is normally greater than the biasing force of spring53, on the other side of said fulcrums. When plunger 44 is depressed,the biasing force of spring 53 is increased to the extent of surpassingthat of spring 82 whereby contact leversV 71 and 72 are caused to movepivotally and open the circuit, as shown in FIG. 3.

Conversely, in the normally open switch embodiment shown in FIG. 9, "thebiasing force of spring 53 is normally greater than that of spring 88whereby the contact levers are maintained in the normally open position.When plunger v44 is depressed, however, the biasing force of spring 88is increased to the extent of overcoming that of spring-53, even thoughthe latter has been increased in force, so thatcontact levers 71 and 72are pivotally moved to close the circuit, as shown in FIG. l0.

,The switch assemblies lillustrated and described herein maybeconnectedto a suitable mounting board 91 or the like (FIG. l0) bymeans of a threaded nut 92 and threaded! ring 93 engaging the peripheralthreads 38 of bushing 37. f i

Inthe specication, there is explained the principles of the invention,and the best mode in which it is contemi plated applying thoseprinciples, so as to distinguish the smears pointed out and distinctlyclaimed the part, mode or combination which the invention or discoveryis claimed.

While there is shown and described certain preferred embodiments of theinvention, it will be understood that modifications and changes may bemade without departing from the function and scope thereof, as will beclear to those skilled in the art.

It is claimed:

l. A momentary switch comprising a base, a pair of spaced apartstationary contacts mounted in said base, a pair of separate andindependent contact levers each pivotally supported intermediate itsrespective ends in said base, each lever being operative to establishelectrical connection with a respective stationary contact, first springbiased means operative on both contact levers for simultaneously closingthe electrical circuits between said levers and their respectivestationary contacts, and second spring biased means operative upon bothcontact levers for simultaneously opening the electrical circuitsbetween said levers and their respective stationary contacts, saidsecond spring biased means establishing electrical connection betweensaid contact levers.

2. A switch according to claim l wherein the normal biasing strength ofone of said means is greater than the normal biasing strength of theother means according as the switch is intended to be normally closed ornormally open, and further comprising means for increasing the biasingstrength of the means of normally lesser strength to overcome thebiasing force of the other spring biased means.

3. A momentary switch comprising a base, a pair of spaced apartstationary contacts mounted in said base, a pair of contact leverspivotally supported on said base, each lever being operative toestablish electrical connection with a respective stationary contact, afirst spring biased actuator bar operative upon both contact levers toproduce positive pivotal motion of the latter in one direction to closethe circuit between said levers and said stationary contactssimultaneously, and a second spring biased actuator bar operative uponboth contact levers to produce positive pivotal motion of the latter inthe opposite direction to open the circuit between said levers and saidstationary contacts simultaneously, said second bar establishingelectrical connection between said contact levers,

4. A momentary switch comprising a base, a pair of spaced apartstationary contacts mounted in said base, a pair of separate andindependent contact levers each pivotally supported intermediate itsrespective ends in said base, each lever being operative to establishelectrical connection with a respective stationary contact, first springbiased means operative on both contact levers for simultaneously closingthe electrical circuits between said levers and their respectivestationary contacts, and second spring biased means operative upon bothcontact leversfor -simultaneouslyopening the electrical circuits betweensaid levers and their respective stationary contacts, said second springbiased means establishing electrical connection between said contactlevers, the normal biasing strength of one of said means beingdetermined to be greater than the normal biasing strength of the othermeans according as the switch is intended to be normally closed ornormally open.

5. A momentary switch comprising a base, a pair of spaced apartstationary contacts mounted in said' base, a pair of separate andindependent contact levers yeach pivotally supported intermediate itsrespective ends in said base, each lever being operative to establishelectrical connection with a respective stationary contact, first springbiased means operative on both contact levers for simultaneously closingthe electrical circuits between saidy levers and their respectivestationary contacts, and second spring biased means operative upon bothcontact levers for simultaneously opening the electrical circuitsbetween said leversv and their respective stationary contacts, saidsecond spring biased means establishing electrical connection betweensaid contact levers, the normal biasing strength of one of said meansbeing determined to be greater than the normal biasing strength of theother means according as the switch is intended to be normally closed ornormally open, and means operative upon the spring biased means ofnormally lesser strength to increase the biasing force thereof toovercome the biasing force of the other spring biased means.

6. A switch comprising a base, a pair of spaced apart stationarycontacts mounted in said base, a pair of contaot levers, each leverhaving a fulcrum intermediate its ends by which it is pivotallysupported in said base, each lever being operative to establishelectrical connection with a respective stationary contact, irst springbiased means operative on both of said levers on one side of theirrespective fulcrutrns for simultaneously closing the electrical circuitsbetween said levers yand the respective stationary cont-acts, and secondspring biased means operative on both levers on the opposite sides ofthe respective fulcrums for simultaneously opening the electricalcircuits between said levers and their respective stationary contacts,said second spring biased means establishing electrical connectionbetween said contact levers.

7. A switch according to claim 6 wherein the normal biasing strength ofone of said means is greater than the normal biasing strength of theother means according as the switch is intended to be normally closed ornorm-ally open, and further comprising means for increasing the biasingstrength of the means of normally lesser strength to overcome thebiasing force of t-he other spring biased means.

8. A momentary switch comprising a base, a pair of spaced apartstationary contacts mounted in said base, a pair of separate andindependent contact levers each pivotally supported intermediate itsrespective ends in said base, one portion of each lever being operativeto establish electrical connection with a respective stationaml contact,first spring biased means normally maintaining both of said leverssimultaneously in contact with said respective stationary contacts,second spring biased means bearing simultaneously upon another portionof each of said levers, a plunger operative upon the second springbiased means to increase the strength thereof to surpass that o-f therst spring biased means whereby said levers are caused to move pivotallyand open thecircuits between said levers and their respective stationarycontacts.

9'. A switch according to claim 8 wherein said second spring biasedmeans establishes electrical connection between said contact levers.

l0. A momentary switch comprising a frame, a pair of spaced apartstationary contacts mounted in said frame, a vpair of contact leverspivotaily supported in said frame, each lever being operative toestablish electrical connection with a respective stationary contact, afirst element positioned against a first portion of each of said levers,a rst spring in said frame bearing upon said first element and causingthe latter normally to urge both of said levers simultaneously intocircuit closing relationship with their respective stationary contacts,a second element in said frame, a second spring in said frame bearingupon said second element and causing the latter yieldably to bear uponanother portion of each of said levers, and a third element operable Iatwi'll upon said second spring for increasing the biasing strengththereof to the extent of surpassing the biasing strength of said rstspring whereby said levers are simultaneously moved pivotally by saidsecond element into -an open circuit position relative to theirrespective stationary contacts.

1l. Aswitch according to claim 10 wherein said third element establisheselectrical connection between said contact levers.

12. A switch acconding to claim l0, and further cornprising -a fourthelement positioned between said third element and corresponding portionsof both of said levers, said fourth element establishing electricalconnection between said levers, said fourth element being maintained inposition by the biasing action of said second spring.

13. A switch according to claim 10, and further comprising spring meansin said frame and operable upon said third element for normallymaintaining the latter in a normally non-operating position.

14. A momentary switch comprising a frame, a. pair of spaced apartstationary contacts mounted in said frame, a pair of contact leverspivotally supported in said frame, each `lever being operative toestablish electrical connection with a respec-tive stationary contact, aplunger mounted in said frame, a first spring in said'frame normallymaintaining said plunger in a non-operating position, a second springpositioned within said plunger, a first element, said second springbearing upon said rst element and causing the latter to bear upon aportion of each of said levers, a second element in said frame, a thirdspring of greater biasing strength than said second spring in said frameand bearing upon said second element to cause the l-atter to normallyurge both of said levers simultaneously into circuit closing positionrelative to their respective stationary contacts, said plunger beingoperable at will to increase the biasing strength of said second springbeyond that of said third spring and to cause said first element topivotally move said Contact levers simultaneously into the open circuitposition against the pressure `of said third spring.

A switch according to claim 14 wherein said second element establisheselectrical connection between said two contact levers.

16. A momentary switch comprising a base, a pair of spaced apartstationary contacts mounted in said base, a pair lof separate andindependent contact levers each pivotally supported intermediate itsrespective ends in said base, one portion of each lever being operativeto establish electrical connection with a respective stationary contact,first spring biased means normally maintaining both of said leverssimultaneously spaced Yapart from their respective stationary contacts,second spring biased means bearing simultaneously upon another portionof each of said levers, a plunger operative upon the second springbiased means to increase the strength thereof to surpass that of thefirst spring biased means whereby said levers are caused to movepivotally -and close the electrical circuits between said levers andtheir respective stationary contacts.

17. A switch accordingV to claim 16 wherein said second spring biasedmeans establishes electrical connection between said contact levers.

18. A momentary switch comprisingA aframe, a pair of spaced .apartstationary contacts mounted in said frame, a pair of contact vleverspivotally supported in said frame, each lever being operative toestablish elec-V trical connection with a'respective stationary contact,a

first element positioned against alirst portion of each of said levers,a iirst spring in said frame bearing upon said first element and causingthe latter to normally maintain both of said levers simultaneouslyspaced apart from their respective stationary contacts, a second elementin said frame, a second spring in said frame bearing upon said secondelement and causing the latter yieldably to bear upon another portion ofeach of said levers, and a third element operable at will upon saidsecond spring for increasing the biasing strength thereof to the extentof surpassing .the biasing strength of said first spring whereby saidlevers are simultaneously moved pivotally by said second element into aclosed circuit position relative to their respective stationarycontacts.

19. A switch according to claim 18 wherein said third elementestablishes electrical connection between said contact levers.

20. A switch according to claim 18, and further comprising a fourthelement positioned between said third element and corresponding portionsof both of said levers, said fourth element establishing electricalconnection between said levers, said fourth element being maintained inposition by the biasing action of said lirst spring.

2l. A switch according to claim 18, and further cornprising spring meansin said frame and operable upon said third element for normallymaintaining the-latter in a normally non-operating position.

22. A momentary switch comprising a frame, a pair of spaced apartstationary contacts mounted in said frame, a pair of contact leverspivotally supported in said frame, each lever being `operative toestablish electrical connection with a respective stationary contact, aplunger mounted in said frame, a first spring in said frame normallymaintaining said plunger in a non-operating position, a second springpositioned within said plunger, a first element, said second springbearing upon said first element and causingv the latter to bear upon aportion of each of said levers, a second element in said frame, a thirdspring of greater biasing strength than said second spring in said frameand bearing upon said second element to cause the latter to normallymaintain both of said levers simultaneously spaced apart from theirrespective stationary contacts, said plunger being operable at will toincrease the biasing strength of said second spring beyond that of saidthird spring and to cause said first element to pivotally move saidcontact levers simultaneously into contact'with their respectivestationary contacts against the pressure of said third spring.

23. A` switch according to claim 22 wherein said' second elementestablishes electrical connection between said two contact levers.

References Cited-in the file of this patent UNITED VSTATES PATENTS2,420,880 Hetherington May 20, 1947

